Install

Usage

Command Line

Usage: autocannon [opts] URL
URL is any valid http or https url.
If the PORT environment variable is set, the URL can be a path. In that case 'http://localhost:$PORT/path' will be used as the URL.
Available options:
-c/--connections NUM
The number of concurrent connections to use. default: 10.
-p/--pipelining NUM
The number of pipelined requests to use. default: 1.
-d/--duration SEC
The number of seconds to run the autocannnon. default: 10.
-a/--amount NUM
The amount of requests to make before exiting the benchmark. If set, duration is ignored.
-S/--socketPath
A path to a Unix Domain Socket or a Windows Named Pipe. A URL is still required in order to send the correct Host header and path.
--on-port
Start the command listed after -- on the command line. When it starts listening on a port,
start sending requests to that port. A URL is still required in order to send requests to
the correct path. The hostname can be omitted, `localhost` will be used by default.
-m/--method METHOD
The http method to use. default: 'GET'.
-t/--timeout NUM
The number of seconds before timing out and resetting a connection. default: 10
-T/--title TITLE
The title to place in the results for identification.
-b/--body BODY
The body of the request.
Note: This option needs to be used with the '-H/--headers' option in some frameworks
-i/--input FILE
The body of the request. See '-b/body' for more details.
-H/--headers K=V
The request headers.
-B/--bailout NUM
The number of failures before initiating a bailout.
-M/--maxConnectionRequests NUM
The max number of requests to make per connection to the server.
-O/--maxOverallRequests NUM
The max number of requests to make overall to the server.
-r/--connectionRate NUM
The max number of requests to make per second from an individual connection.
-R/--overallRate NUM
The max number of requests to make per second from an all connections.
connection rate will take precedence if both are set.
NOTE: if using rate limiting and a very large rate is entered which cannot be met,
Autocannon will do as many requests as possible per second.
-D/--reconnectRate NUM
Some number of requests to make before resetting a connections connection to the
server.
-n/--no-progress
Don't render the progress bar. default: false.
-l/--latency
Print all the latency data. default: false.
-I/--idReplacement
Enable replacement of [<id>] with a randomly generated ID within the request body. default: false.
-j/--json
Print the output as newline delimited json. This will cause the progress bar and results not to be rendered. default: false.
-f/--forever
Run the benchmark forever. Efficiently restarts the benchmark on completion. default: false.
-s/--servername
Server name for the SNI (Server Name Indication) TLS extension.
-x/--excludeErrorStats
Exclude error statistics (non 2xx http responses) from the final latency and bytes per second averages. default: false.
-v/--version
Print the version number.
-h/--help
Print this menu.

There are two tables: one for the request latency, and one for the request volume.

The latency table lists the request times at the 2.5% percentile, the fast outliers; at 50%, the median; at 97.5%, the slow outliers; at 99%, the very slowest outliers. Here, lower means faster.

The request volume table lists the amount of requests sent and the amount of bytes downloaded. These values are sampled once per second. Higher values mean more requests were processed. In the above example, 4.78 MB was downloaded in 1 second in the worst case (slowest 1%). Since we only ran for 5 seconds, there are just 5 samples—the Min value and the 1% and 2.5% percentiles are actually all the same sample. With longer durations these numbers will differ more.

When passing the -l flag, a third table lists all the latency percentiles recorded by autocannon:

This can give some more insight if a lot (millions) of requests were sent.

Programmatically

'use strict'

constautocannon=require('autocannon')

autocannon({

url:'http://localhost:3000',

connections:10,//default

pipelining:1,// default

duration:10// default

},console.log)

API

autocannon(opts[, cb])

Start autocannon against the given target.

opts: Configuration options for the autocannon instance. This can have the following attributes. REQUIRED.

url: The given target. Can be http or https. REQUIRED.

socketPath: A path to a Unix Domain Socket or a Windows Named Pipe. A url is still required in order to send the correct Host header and path. OPTIONAL.

connections: The number of concurrent connections. OPTIONAL default: 10.

duration: The number of seconds to run the autocannon. Can be a timestring. OPTIONAL default: 10.

amount: A Number stating the amount of requests to make before ending the test. This overrides duration and takes precedence, so the test won't end until the amount of requests needed to be completed are completed. OPTIONAL.

timeout: The number of seconds to wait for a response before . OPTIONAL default: 10.

pipelining: The number of pipelined requests for each connection. Will cause the Client API to throw when greater than 1. OPTIONAL default: 1.

bailout: The threshold of the number of errors when making the requests to the server before this instance bail's out. This instance will take all existing results so far and aggregate them into the results. If none passed here, the instance will ignore errors and never bail out. OPTIONAL default: undefined.

method: The http method to use. OPTIONALdefault: 'GET'.

title: A String to be added to the results for identification. OPTIONAL default: undefined.

body: A String or a Buffer containing the body of the request. Insert one or more randomly generated IDs into the body by including [<id>] where the randomly generated ID should be inserted (Must also set idReplacement to true). This can be useful in soak testing POST endpoints where one or more fields must be unique. Leave undefined for an empty body. OPTIONAL default: undefined.

headers: An Object containing the headers of the request. OPTIONAL default: {}.

setupClient: A Function which will be passed the Client object for each connection to be made. This can be used to customise each individual connection headers and body using the API shown below. The changes you make to the client in this function will take precedence over the default body and headers you pass in here. There is an example of this in the samples folder. OPTIONAL default: function noop () {}.

maxConnectionRequests: A Number stating the max requests to make per connection. amount takes precedence if both are set. OPTIONAL

maxOverallRequests: A Number stating the max requests to make overall. Can't be less than connections. maxConnectionRequests takes precedence if both are set. OPTIONAL

connectionRate: A Number stating the rate of requests to make per second from each individual connection. No rate limiting by default. OPTIONAL

overallRate: A Number stating the rate of requests to make per second from all connections. connectionRate takes precedence if both are set. No rate limiting by default. OPTIONAL

reconnectRate: A Number which makes the individual connections disconnect and reconnect to the server whenever it has sent that number of requests. OPTIONAL

requests: An Array of Objects which represents the sequence of requests to make while benchmarking. Can be used in conjunction with the body, headers and method params above. The Objects in this array can have body, headers, method, or path attributes, which overwrite those that are passed in this opts object. Therefore, the ones in this (opts) object take precedence and should be viewed as defaults. Check the samples folder for an example of how this might be used. OPTIONAL.

idReplacement: A Boolean which enables the replacement of [<id>] tags within the request body with a randomly generated ID, allowing for unique fields to be sent with requests. Check out an example of programmatic usage can be found in the samples. OPTIONAL default: false

forever: A Boolean which allows you to setup an instance of autocannon that restarts indefinitely after emiting results with the done event. Useful for efficiently restarting your instance. To stop running forever, you must cause a SIGINT or call the .stop() function on your instance. OPTIONAL default: false

servername: A String identifying the server name for the SNI (Server Name Indication) TLS extension. OPTIONAL default: undefined.

excludeErrorStats: A Boolean which allows you to disable tracking non 2xx code responses in latency and bytes per second calculations. OPTIONAL default: false.

cb: The callback which is called on completion of a benchmark. Takes the following params. OPTIONAL.

err: If there was an error encountered with the run.

results: The results of the run.

Returns an instance/event emitter for tracking progress, etc.

autocannon.track(instance[, opts])

Track the progress of your autocannon, programmatically.

instance: The instance of autocannon. REQUIRED.

opts: Configuration options for tracking. This can have the following attibutes. OPTIONAL.

outputStream: The stream to output to. default: process.stderr.

renderProgressBar: A truthy value to enable the rendering of the progress bar. default: true.

renderResultTable: A truthy value to enable the rendering of the results table. default: true.

renderLatencyTable: A truthy value to enable the rendering of the advanced latency table. default: false.

progressBarString: A string defining the format of the progress display output. Must be valid input for the progress bar module. default: 'running [:bar] :percent'.

Client API

This object is passed as the first parameter of both the setupClient function and the response event from an autocannon instance. You can use this to modify the requests you are sending while benchmarking. This is also an EventEmitter, with the events and their params listed below.

client.setHeaders(headers): Used to modify the headers of the request this client iterator is currently on. headers should be an Object, or undefined if you want to remove your headers.

client.setBody(body): Used to modify the body of the request this client iterator is currently on. body should be a String or Buffer, or undefined if you want to remove the body.

client.setHeadersAndBody(headers, body): Used to modify the both the headers and body this client iterator is currently on.headers and body should take the same form as above.

client.setRequest(request): Used to modify the both the entire request that this client iterator is currently on. Can have headers, body, method, or path as attributes. Defaults to the values passed into the autocannon instance when it was created. Note: call this when modifying multiple request values for faster encoding

client.setRequests(newRequests): Used to overwrite the entire requests array that was passed into the instance on initiation. Note: call this when modifying multiple requests for faster encoding

Client events

The events a Client can emit are listed here:

headers: Emitted when a request sent from this client has received the headers of its reply. This received an Object as the parameter.

body: Emitted when a request sent from this client has received the body of a reply. This receives a Buffer as the parameter.

response: Emitted when the client has received a completed response for a request it made. This is passed the following arguments:

statusCode: The http status code of the response.

resBytes: The response byte length.

responseTime: The time taken to get a response for the initiating the request.

Example using the autocannon events and the client API and events:

'use strict'

constautocannon=require('autocannon')

constinstance=autocannon({

url:'http://localhost:3000',

setupClient: setupClient

},(err,result)=>handleResults(result))

// results passed to the callback are the same as those emitted from the done events

instance.on('done', handleResults)

instance.on('tick',()=>console.log('ticking'))

instance.on('response', handleResponse)

functionsetupClient(client){

client.on('body',console.log)// console.log a response body when its received